Senate Republican leaders plan to filibuster President Barack Obama's proposal to raise the minimum wage to $10.10 an hour when it comes up for an initial test vote Wednesday, and are pushing for a vote soon on the Keystone XL pipeline instead.

“Cloture will not be invoked,” said Senate Minority Whip John Cornyn, R-Texas.

“Minimum wage is an important issue for the American people,” said Senate Majority Leader Harry Reid, D-Nev. “All that we are asking is that we are allowed to get on the bill.”

The bill is part of an agenda Democrats unveiled before the recess that is focused on helping the middle class.

But Republicans charge Democrats with using the minimum wage issue for political gain.

"For the Democrats it’s a political exercise, so I think they figure they will get something out of it," Thune said. "But I think we are pretty unified against this just because it's a bad policy that hurts jobs and the economy. We don't think that this is something we ought to be talking about now." Republicans argue that it could cost 500,000 jobs, citing a February study by the Congressional Budget Office. The same study also said the bill would lift 900,000 workers above the poverty line and give millions more raises.

The National Federation of Independent Businesses also opposes the measure. The group contends that the bill would be burdensome to small businesses, which already face significant hurdles.

“With increases to health care costs, higher taxes, more costly regulations, and now a dramatic minimum wage increase, small business owners simply can’t afford another excessive government mandate,” said NFIB Manager of Legislative Affairs Ashley Fingarson, in a release. It could not be clearer from our studies and the recent Congressional Budget Office report — raising the minimum wage will kill jobs and stifle economic output.”

And Democrats were already telegraphing that defeat of the measure on Wednesday was likely, stressing that they intend to bring the measure back up if it goes down.

"I hope it passes," Senate Health, Education, Labor and Pensions Chairman Tom Harkin, D-Iowa, said at a press conference Tuesday morning. "But I assure you if it doesn't pass tomorrow it will be back. We are not going to give up."

After the press conference, Harkin said it typically takes more than one try get a minimum wage increase into law.

"The history of all minimum wage bills [is] we don’t get it through, then we come back and we finally get it through," Harkin said.

"I don't know when … but we'll be back," Harkin continued.

"If the Republicans are concerned about it they may want to vote on it now before we get too close to the election," Harkin said.

"I think more and more people are going to be talking about this in local communities. … Yeah, I think the pressure is going to mount," Harkin quipped.

Meanwhile Republicans were looking to next week when the Senate is expected to move to an energy efficiency bill sponsored by Sen. Jeanne Shaheen, D-N.H., and Sen. Rob Portman, R-Ohio.

Senate Minority Leader Mitch McConnell, R-Ky., said he is looking to have a broad energy debate once the Senate gets on the bill. He also hopes the process allows for four or five energy related amendments, including approval of the Keystone XL pipeline.

"We are in discussions on going forward with the Portman-Shaheen energy bill," said Senate Minority Leader Mitch McConnell, R-Ky. "We haven’t had a full scale energy debate since 2007. We believe that this bill should have a process for consideration that allows four or five significant energy related measures."

Reid said he was prepared to allow a vote on Keystone. "I'm open to anything that will move energy efficiency," he said.

"I’ve talked about it with the caucus," Reid continued, adding that he has recently met with Sen. Mary Landrieu, D-La., Sen. John Hoeven, R-N.D., and Sen. Mark Begich, D-Alaska, who all back the pipeline.

Landrieu and Begich are both in relatively tight reelection campaigns and, with large oil and gas industries in their respective states, getting the pipeline through the Senate would be a political and policy win for them.

Reid added that Republicans have been indecisive over whether they wanted an amendment expressing the sense of the Senate, which is nonbinding or something stronger. "I can't agree to something that I don't know what it is," Reid said.

But Thune said there is no indecision on their part.

“We ought to have a binding vote that would force that issue,” he said. “Democrats are talking about having a sense of the Senate vote, which would be a nonbinding meaningless vote. We actually ought to have a vote that matters. One where we are really putting people on record in terms of whether they support this job creating measure."

Along with Keystone, Republicans are interested in offering amendments blocking regulations on coal, and boosting liquid natural gas exports.